Pipe wiper



April 3, 1956 H, J, COX

PIPEWIPER Filed April 28, 1954 INVENToR. Howard J. COX

ATTORNEYS PEE WEER Howard J. Cox, @Mahoma City, Ghia.

Application April 28, i954, Serial No. 26,2%

4 Claims. (Cl. 16o- 170) This invention relates to pipe wipers and moreparticularly to a structure for wiping the inside of a drill pipe or thelike used in drilling wells as said drill pipe is removed from a wellbeing drilled.

It is now common practice in the drilling of boreholes for oil and thelike to use various kinds and specic gravities of drilling mud which iscirculated in the borehole and tools during the drilling operations.This mud contains expensive chemicals including mild acids and causticsto provide better non-caving borehole conditions, better cooling of thedrilling bit, and better control over gas blowouts, which could resultin injury to the drilling crew and damage to equipment. A certain amountof this drilling mud always escapes on the rig floor when the drill pipeis being pulled from the borehole to change bits, causing a wet, slickfloor condition where the crew is working and making up or breaking outthe drill pipe in running in or out of the borehole. In freezingtemperatures this wet floor freezes, making it even more slippery anddangerous for the drilling crew. While several types of outside drillpipe wipers are presently in use in the drilling industry to help solvethis hazardous and wasteful problem, the inside of the drill pipe neverdrains completely due to the heavy mud weights and as a result the mudadhering to the inside of the drill pipe drips and runs onto the derrickfloor as the pipe is being set back in the derrick and stored thereinwhile the remainder of the drill pipe is being pulled from the boreholeand is again run into the borehole. Also, the wet condition on theinside of the drill pipe due to the mud adhering thereto causes rust andcorrosion to form in the inside of the pipe while not in use.

The objects of the present invention are to provide a pipe wiper forremoving drilling mud from the inside of drill pipe and thereby keep theinside of the drill pipe clean and dry as it is withdrawn from theborehole whereby the above mentioned hazardous and wasteful condition iscompletely overcome; to provide a pipe wiper for the inside of drillpipe that combines a buoyant structure adapted to iioat in drilling mudwith flexible wiping members supported on the buoyant member andextending above the level of the drilling mud whereby as the drill pipeis removed from a well the wiper remains at substantially the sameelevation to wipe the inside of said pipe; to provide such a pipe wiperwith an air chamber for buoyancy with a weighted lower end of suitableproportions relative to the specific gravity of the drilling mud wherebythe air chamber provides buoyancy to retain the wiping members above thelevel of the mud and the weighted lower end prevents the frictionbetween the ilexible wiping members and pipe from raising the pipe wiperfrom the drilling mud as the pipe is removed from the borehole; toprovide such a pipe wiper structure that will permit bypass of drillingfluid should it become necessary to circulate drilling rnud in theborehole at any time while the pipe wiper is in service; and to providea pipe wiper for the inside of drill pipe 2,740,480 Patented Apr. 3,1956 that is economical to manufacture, easily assembled and efficientin use for cleaning and drying the inside of drill pipe as it is beingremoved from a borehole. Y

In accomplishing these and other objects of the present invention I haveprovided improved details of structure the preferred forms of which areillustrated in the accompanying drawings, wherein:

Fig. l is an elevational view of the pipe wiper inside of a drill pipein a borehole.

Fig. 2 is a vertical sectional view through the pipe wiper.

Fig. 3 is a transverse sectional view through the pipe wiper on the line3-3, Fig. 2.

Fig. 4 is a transverse sectional view through the pipe wiper air chamberon the line 4 4, Fig. 2.

Fig. 5 is a transverse sectional view through the weighted end of thepipe wiper on the line 5;-5, Fig. 2.

Referring more in detail to the drawings:

1 designates a pipe wiper embodying the features of the presentinvention and adapted to wipe the bore 2 of drill pipe 3 as it isremoved from a borehole 4. In the rotary drilling of oil wells and thelike it is common practice to have a drill bit on the lower end of oneor more drill collars with the uppermost collar connected to thelowermost joint of a string of drill pipe sections 3, the drill pipesections being connected together by threaded joints as at 5. The uppersection of the drill pipe is connected to a Kelly rod that extendsthrough a turntable 6 suitably mounted in a derrick floor to rotate theKelly rod and drill pipe connected thereto. It is common practice topump drilling mud downwardly through the Kelly rod, drill pipe sections,drill collars and through the bit, the mud flowing upwardly in theborehole around the drill pipe and then through a suitable channel 7 toa collecting basin from which it is pumped in the circulation of thedrilling mud. When it is necessary to change the bits or otherwiseservice the borehole the drill pipe is removed therefrom, the drill pipebeing pulled upwardly through the turntable by suitable elevators andthen the main string held while the sections are disconnected. Duringsuch operation the drilling mud tends to remain at substantially thesame level, as at 8, both inside and outside the drill pipe.

The pipe wiper l is adapted to be inserted in the drill pipe bore 2 whenthe Kelly rod is removed from the uppermost section of the drill pipe.The pipe wiper 1 has a weight portion 9 at'the lower end of a buoyantchamber it) and a plurality of liexible wiping members l1 suitablysupported above the buoyant chamber 10. In the illustrated structurethere is a tubular shell l2 of smaller diameter than the smallestportion of the bore through the drill pipe section. The lower end of theshell is closed by a plug i3 of suitable metal or the like to providesuiiicient weight to cooperate with the buoyant chamber llt) whereby theentire structure will float in the drilling mud and the weight willovercome the friction between the wiping members il and the inside ofthe walls of the drill pipe. The plug 13 has a threaded upper portion l@which is screwed into the lower portion of the shell with a portion ofthe plug extending from the shell having a tapered or curved contourdefining a substantially pointed lower end 15. A plurality oflongitudinal grooves are spaced around the periphery of the lower end ofthe plug i3 to serve as bypasses for the drilling mud as laterdescribed.

The upper end of the shell l2 is secured to a closure member i7 providedwith a stem extending therefrom substantially coaxially of the shell 12.In the illustrated structure the closure Il? is in the form of a pipereducer bushing, having an externally threaded portion 19 threaded intothe upper end of the shell l2 with an internally threaded boss Ztlextending upwardly therefrom.

4trated in Fig. l. borehole in lthe customary manner. elevated the pipewiping apparatus remains substantially Thesshank 1S is preferablytubular for lightness in Weight and has a lower end threaded into theinternally threaded boss 20 of the reducer bushing or closure 17. Theupper end of the tubular shank ii is suitably closed as by a pipe plug21. While the closures of the air chamber fformed by the shell l2 andtubular shank lS are provided with threaded lconnections it is obviouswelding Jor Iother suitable connections may be used that will makewatertight joints.

The wiping members 1l are preferably of neoprene or other suitableflexible material and are preferably circular disks' with bores 22tierein for slceving the disks on the shank 1S. Suitable spacers 23 aresleeved on the shank between the flexible wiping disks to providesuitable spacing therebetween. The wiping disks and spacers are heldfonfthe shank `1S by a nur 2d threaded on the upper end of the shank 18,said nut being tightened to ,prevent any VVVendwis'e movement of thewiping members or spacers.

The wiping disks are preferably provided with a plurality of spacednotches cr cuts 25 arranged around the periphery ,thereof to facilitatethe bending of the edges of the wiping disks whereby they will conformto the `interior yor bore of the drill pipe and provide proper wipingcontact therewith. The wiping disks may be made 'in various thicknessesand sizes for best wiping action on yvarious Vsize drill pipe and alsomay be any suitable num- :ber whereby the wiping will clean the bore ofthe drill pipe.

lnausing a pipe wiper constructed and assembled as described, the Kellyrod is removed from the uppermost secn tionof Vdrill pipe and the pipewiper inserted into the Vbore of `said drill pipe with the weighted end9 inserted vforemost in said drill pipe. The weight of the plug and"shel'l'will cause the pipe wiper assembly to move downwardly `inthedrill pipe and into the drilling mud and :then the buolancy provided bythe buoyant chamber 10 will 'cause the structure to iloat in thedrilling mud with the pipe wipers 11 above the level of said mud, esillus- Then the drill pipe is pulled from the As the drill pipe is iinthe -same position relative to the level of the drilling Vmud, fthewipers wiping the drilling mud from the bore yof vthe drill pipe as saiddrill pipe is elevated.

ln vthe event the drill pipe should become stuck or 'for other reason itis necessary to circulate 'the drilling mud in the drill pipe andborehole, the `discharge of the mud pump is connected to the drill pipeand the mud pumped downwardly therein. rfhe pump pressure acting on thepipe wiper will force said pipe wiper downwardly of the drill pipe untilthe buoyancy of the pipe wiper in the drilling mud is such that the pumppressure can force the drilling mud by the pipe wipers 1l. However, inmost instances the pump pressure will force the pipe wiper assemblydownwardly in the drill pipe until the plug i3 engages the bore of theuppermost drill collar, which bore is substantially smaller than thebore of the drill pipe. While the plug i3 would tend to close the Aborein the drill collar, the grooves i6 provide passages for thedrilling mudto permit the circulation of the drilling mud in the borehole. After thecirculation of the drilling mud is stopped and the pump disconnected thebuoyancy of the pipe wiper structure will cause it to rise to thesurface of the drilling mud in the drill pipe and then the drill pipepulling operations may be resumed. When the lowcrmost section of thedrill pipe is disconnected from the uppermost drill collar the pipewiper is removed from the lower end of said lowermost drill pipesection.

It is believed obvious that l have provided a simple, efficient pipewiper structure for cleaning the inside of drill pipe as it is removedfrom boreholes.

What I claim and desire to secure by Letters Patent is:

1. AV pipe wiper for wiping mud and drilling uids from the inside ofwell drill pipe as said pipe is removed from member having a relativelyheavy weighted tapered end, said chamber member being smaller inexternal diameter than the smallest bore of drill pipe in which thewiper is to be used, an extension member smaller in diameter than thebuoyant chamber member arranged axially of said chamber member andextending therefrom at the end opposite the weighted tapered end of thebuoyant chamber, a plurality of flexible wiping members sleeved on theextension member, said wiping members being of suitable size with slitsin the peripheral portion thereof whereby said peripheral portionresiliently and wipingly engages the interior of a drill pipe, meansspacing the flexible wiping members on the extension member, and meanson the extension member for retaining the wiping members and spacingmeans against axial movement on the extension, said buoyant chamber andweighted end being proportioned whereby the weight overcomes thefriction between the wiping members and drill pipe to effect`gravitational movement thereof downwardlyin the drill ,pipe and thebuoyancy of the chamber ,member in the drilling fluids causes saidchamber memberto 'float and maintain the wiping members above the huidlevel.

2. Apipe wiper for wiping mud and drilling uids from the inside of welldrill pipe as said pipe is removed from a borehole comprising, anelongate substantially cylindrical shell, aplug member secured to oneend of the shell in closing relation thereto, a substantially conicalextension on said plug member having longitudinal grooves in theexterior thereof, an extension of smaller external diameter than theshell arranged at the other end of said shell in closing relationthereto to define a buoyant chamber' in the shell, a plurality of spacedflexible wiping members sleeved on the extension, spacing means sleevedon the extension between the wiping members to maintain said wipingvmembers in spaced relation, and means on the extension for retainingthe wiping members and Spacers against axial movement on the extension,said wiping members being of Vsuch size that the peripheral portionsthereof resiliently and wipingly engage the interiorfof the drill pipe,said shell, extension and plug being proportioned whereby the plug formsa weighted end on the shell and the weight thereof overcomes thefriction between the wiping members and drill pipe to effectgravitational movement thereof downwardly in the drillpipeand thebuoyancy of the chamber defined by the shell causes the pipe wiper tofloat in the drilling fluids with the wiping members above the fluidlevel.

3. A pipe wiper for wiping mud and drilling fluids from the inside ofwell drillpipe as said pipe is removed .from a borehole comprising, anelongate substantially cylin drical shell, a plug member secured to oneendof the shell in closing relation thereto, a substantiallyconicalextension on said plug member having longitudinal grooves on theexterior thereof, a tubular extension -of smaller Vexternal diameterthan the shell arranged at the other end of said shell, means closingthe end of the tubular extension remotely from the shell, meansconnecting the adjacent ends of the shell and tubular extension wherebythe shell and extension cooperate to define a buoyant chamber, aplurality of spaced flexible wiping members sleeved on the tubularextension, andmeanson the tubular extension for retaining the wipingmembers ,against axial movement on the tubular extension, said wiping`members being of such size that the peripheral portions `thereofresiliently and wipingly engage the interior of the drill pipe, saidshell, tubular member and plug being proportioned whereby the plug formsa weighted end on the shell and the Weight thereof overcomes thefriction between the wiping members and drill pipe to electgravitational movement thereof downwardly in the drill `pipe and thebuoyancy of the chamber defined bytheshell causes the pipe wiper totloat in the drilling uids with the wiping members above the lluidlevel.

4. Apipe wiper for wiping mud and drilling fluids from the inside ofwell drill pipe as said pipe is removed from a borehole comprising, anelongate substantially cylindrical shell, a plug member secured to oneend of the shell in closing relation thereto, a substantially conicalextension on said plug member having longitudinal grooves on theexterior thereof, a tubular extension of smaller external diameter thanthe shell arranged at the other end of said shell, means closing the endof the tubular eXtension remotely from the shell, means connecting theadjacent ends of the shell and tubular extension whereby the shell andextension cooperate to define a buoyant chamber, a plurality of spacedexible wiping members sleeved on the tubular extension, spacing meanssleeved on the tubular extension between the wiping members to maintainsaid wiping members in spaced relation, means on the tubular extensionfor retaining the wiping members and spacers against axial movement onthe extension, said wiping members being of such size that theperipheral portions thereof resiliently and wipingly engage the interiorof the drill pipe, and slits in the peripheral portion of the wipingmembers to facilitate said peripheral portions conforming to theinterior of the drill pipe, said shell, tubular member and plug beingproportioned whereby the plug forms a weighted end on the shell and theweight thereof overcomes the friction between the wiping members anddrill pipe to effect gravitational movement thereof downwardly in thedrill pipe and the buoyancy of the chamber defined by the shell causesthe pipe wiper to oat in the drilling fluids with the wiping membersabove the uid level.

References Cited inthe le of this patent UNITED STATES PATENTS 175,628Schulte Apr. 4, 1876 1,527,749 Raymond Feb. 24, 1925 2,225,413 Festervanet al. Dec. 17, 1940 2,257,080 Turner Sept. 23, 1941 2,257,784 BrownOct. 7, 1941 2,668,593 Hay Feb. 9, 1954

